Root/include/scsi/libiscsi_tcp.h

1/*
2 * iSCSI over TCP/IP Data-Path lib
3 *
4 * Copyright (C) 2008 Mike Christie
5 * Copyright (C) 2008 Red Hat, Inc. All rights reserved.
6 * maintained by open-iscsi@googlegroups.com
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published
10 * by the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * General Public License for more details.
17 *
18 * See the file COPYING included with this distribution for more details.
19 */
20
21#ifndef LIBISCSI_TCP_H
22#define LIBISCSI_TCP_H
23
24#include <scsi/libiscsi.h>
25
26struct iscsi_tcp_conn;
27struct iscsi_segment;
28struct sk_buff;
29struct hash_desc;
30
31typedef int iscsi_segment_done_fn_t(struct iscsi_tcp_conn *,
32                    struct iscsi_segment *);
33
34struct iscsi_segment {
35    unsigned char *data;
36    unsigned int size;
37    unsigned int copied;
38    unsigned int total_size;
39    unsigned int total_copied;
40
41    struct hash_desc *hash;
42    unsigned char padbuf[ISCSI_PAD_LEN];
43    unsigned char recv_digest[ISCSI_DIGEST_SIZE];
44    unsigned char digest[ISCSI_DIGEST_SIZE];
45    unsigned int digest_len;
46
47    struct scatterlist *sg;
48    void *sg_mapped;
49    unsigned int sg_offset;
50
51    iscsi_segment_done_fn_t *done;
52};
53
54/* Socket connection recieve helper */
55struct iscsi_tcp_recv {
56    struct iscsi_hdr *hdr;
57    struct iscsi_segment segment;
58
59    /* Allocate buffer for BHS + AHS */
60    uint32_t hdr_buf[64];
61
62    /* copied and flipped values */
63    int datalen;
64};
65
66struct iscsi_tcp_conn {
67    struct iscsi_conn *iscsi_conn;
68    void *dd_data;
69    int stop_stage; /* conn_stop() flag: *
70                         * stop to recover, *
71                         * stop to terminate */
72    /* control data */
73    struct iscsi_tcp_recv in; /* TCP receive context */
74    /* CRC32C (Rx) LLD should set this is they do not offload */
75    struct hash_desc *rx_hash;
76};
77
78struct iscsi_tcp_task {
79    uint32_t exp_datasn; /* expected target's R2TSN/DataSN */
80    int data_offset;
81    struct iscsi_r2t_info *r2t; /* in progress solict R2T */
82    struct iscsi_pool r2tpool;
83    struct kfifo r2tqueue;
84    void *dd_data;
85};
86
87enum {
88    ISCSI_TCP_SEGMENT_DONE, /* curr seg has been processed */
89    ISCSI_TCP_SKB_DONE, /* skb is out of data */
90    ISCSI_TCP_CONN_ERR, /* iscsi layer has fired a conn err */
91    ISCSI_TCP_SUSPENDED, /* conn is suspended */
92};
93
94extern void iscsi_tcp_hdr_recv_prep(struct iscsi_tcp_conn *tcp_conn);
95extern int iscsi_tcp_recv_skb(struct iscsi_conn *conn, struct sk_buff *skb,
96                  unsigned int offset, bool offloaded, int *status);
97extern void iscsi_tcp_cleanup_task(struct iscsi_task *task);
98extern int iscsi_tcp_task_init(struct iscsi_task *task);
99extern int iscsi_tcp_task_xmit(struct iscsi_task *task);
100
101/* segment helpers */
102extern int iscsi_tcp_recv_segment_is_hdr(struct iscsi_tcp_conn *tcp_conn);
103extern int iscsi_tcp_segment_done(struct iscsi_tcp_conn *tcp_conn,
104                  struct iscsi_segment *segment, int recv,
105                  unsigned copied);
106extern void iscsi_tcp_segment_unmap(struct iscsi_segment *segment);
107
108extern void iscsi_segment_init_linear(struct iscsi_segment *segment,
109                      void *data, size_t size,
110                      iscsi_segment_done_fn_t *done,
111                      struct hash_desc *hash);
112extern int
113iscsi_segment_seek_sg(struct iscsi_segment *segment,
114              struct scatterlist *sg_list, unsigned int sg_count,
115              unsigned int offset, size_t size,
116              iscsi_segment_done_fn_t *done, struct hash_desc *hash);
117
118/* digest helpers */
119extern void iscsi_tcp_dgst_header(struct hash_desc *hash, const void *hdr,
120                  size_t hdrlen,
121                  unsigned char digest[ISCSI_DIGEST_SIZE]);
122extern struct iscsi_cls_conn *
123iscsi_tcp_conn_setup(struct iscsi_cls_session *cls_session, int dd_data_size,
124             uint32_t conn_idx);
125extern void iscsi_tcp_conn_teardown(struct iscsi_cls_conn *cls_conn);
126
127/* misc helpers */
128extern int iscsi_tcp_r2tpool_alloc(struct iscsi_session *session);
129extern void iscsi_tcp_r2tpool_free(struct iscsi_session *session);
130
131extern void iscsi_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
132                     struct iscsi_stats *stats);
133#endif /* LIBISCSI_TCP_H */
134

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